Design and Development of Universal Counter Wrench and Poly Sleeve/Filler Bushing Removal Tool for Triathlon Limb Salvage Program

Abstract

The objective of the project “Design and Development of Universal Counter Wrench and Poly Sleeve/Filler Bushing Removal Tool for Triathlon Limb Salvage Program” is to make a hinge portfolio which combines the design analogies of global modular replacement system, Modular Rotating Hinge System, Massive Endoprosthesis Tumor System, Stanmore Modular Individualized Lower Extremity System. The work presented in this thesis for “New Product Development Process” of two instruments: Universal Counter Wrench and Poly Sleeve/Filler Bushing Removal Tool. The primary objective of the work is to conceptualize a design which can fulfill the needs and requirements from the surgeon such as functionality, marketing with regards to cost, sterility, cleaning, packaging and manufacturing perspective. And then to check that the design concept is stable and robust. Firstly, literature survey was performed to gain knowledge in the knee surgery portfolio. The hinge is basically third stage and the most complex stage of implantation. The study was divided into two parts. The first part deals with the survivorship aspects of the primary and revision surgeries from around the globe and the second part of the study focused on the comparative study of the implants and the instruments failure of competitors and the major causes of the failure of the hinge construct to have in depth knowledge of the key design concepts of the medical implants and instruments. The process is divided into three phases. In the first phase, the material is finalized depending upon the standards of medical industry and compatibility with the engaging instruments/implants. For this, different available materials are compared based on the desired properties. And then, the documentation was done based on the design inputs from surgeons, cleaning, sterility and marketing. In the second phase, the design conceptualization is carried out. It includes design calculation with regards to engagement with mating component, and then analysis of different concepts is performed. The selected concept is then verified by tolerance analysis with assembly, finite element method, benchtop testing to see how the instrument behaves in surgical environment and to verify the theoretical results. The finalized concept is then prototyped to have a real look and feel of the final product. Finally, the conclusions, learnings and scope for future work is presented.